How air pollution affects the health of marginalized communities in Nipomo Mesa

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Public health officials have known for years that year-round air quality is often poor on Nipomo Mesa in South San Luis Obispo County. This can cause serious health problems for people in the area – esp people of color and low-income people.

Maria, whose last name is withheld for her privacy due to the sensitivity of this topic, has lived in Oceano for 25 years. She is married with four children – and has asthma.

She uses an inhaler several times a day.

“Two years ago I [didn’t use my inhaler much]but now I use it more often,” Maria said.

She said she didn’t always have this problem, but it got worse over the years. She is one of thousands of residents living and working in Oceano and Nipomo who experience negative health effects from polluted air.

Some of this pollution comes from emissions and smoke from forest fires. But much of the particulate matter that people breathe in every day in this area comes from dust and sand blown from the Oceano Dunes.

The San Luis Obispo County Air Pollution Control District (APCD) has investigated the pollution levels of the southern district in depth and frequently issues “Breather Alerts” that notify residents of days with high particulate matter levels.

The Oceano Dunes are known to be responsible for air pollution on Nipomo Mesa as the winds blow up dust and sand.

“It’s windier. And [it’s always been] windy, but not like this,” Maria said.

Maria is right that it is windier lately. She said she thinks the extra wind may be blowing more sand than usual into the air and affecting her breathing.

Megan Field of the San Luis Obispo County APCD said the agency has been notifying residents about days with high particulate matter this year. Although, she said, air quality monitors show that pollution is actually less than it was.

“When we compare what we’re seeing right now to even five years ago, those peaks — the parts per million that we’re seeing — are significantly less than what we were seeing five, ten years ago,” Field said.

However, the impact on public health is not going away. Maria has been exposed to dust for decades. She said that her neighbor’s grandson also has asthma, and Maria’s daughter, Liliana, also has breathing problems.

Local and state air resources boards, along with public health departments, know this as a problem — especially among minority and low-income communities.

“We recognize that there are certain areas in our county — the Nipomo Mesa area and part of the Oceano area — where people are more affected by the harmful effects of air pollution,” Field said.

Although air pollution concentrations may be the same at all economic levels, low-income people and people of color bear a disproportionate health burden from this air pollution.

According to the American Lung Association, much of this disproportionate impact across the country is related to things like exposure, susceptibility and access to health care.


Many people on Nipomo Mesa work outside in farm fields like this.

“We know nationally that low-income communities — and especially among people of color — have higher rates of respiratory disease, particularly asthma,” said Dr. Penny Borenstein, San Luis Obispo County Public Health Officer.

Borenstein said the Department of Public Health does not have local data reflecting this trend, but they are extrapolating.

“It stands to reason that this would not be different in our community — that we would see a greater impact in these subpopulations,” Dr. Borenstein said.

Many farm workers in Nipomo Mesa are outside all day and breathe in more polluted air than someone working in an office or in an air-conditioned home.

But for people who are already earning a low wage with no sick time, it’s hard to sacrifice their income and come home. APCD’s Field said the agency knows that dedicating funds to clean their home air is even more of a challenge.

“On top of that bad air pollution, as they work outdoors all day, they come home and their filtration systems may not be up to par either.” So their indoor air quality is also poor,” Field said.

The barriers don’t stop there.

In the second article of this series, we will meet Soledad, one of Maria’s friends, who picks fruit in Mesa for work.

We’ll hear about her experience working in agriculture and explore workers’ Mesa roadblocks that worsen their exposure to poor air quality and prevent them from seeking care.

Rachel Showalter reported this story while participating in the USC Annenberg Center for Health Journalism’s 2022 California Fellowship, which provided training, mentoring and funding to support this project.

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